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Chapter 7 · From Wood to Pulp - Cellulose
7
BOX: Hemp - A Plant with Many Faces
Hemp (Cannabis sativa) is one
of the oldest crops on earth:
Archeologists found fibers of
wild hemp in a cave which are
already about 30,000 years old.
The first systematic cultivation
of hemp probably took place
6000 years ago in China. Hemp
has been known in Europe since
ancient times and has been
cultivated and intensively used
as an important renewable
raw material in many regions.
Advantageously, hemp can be
cultivated without difficulty since
it is resistant to pests (. Fig. 7.3).
The different parts of the
hemp plant can be used very
differently:
5 The fibers of the hemp
stalks are an important raw
material for resistant textiles
as well as for ship ropes
and rigging. As already
practiced by the Chinese
in ancient times, hemp can
also be used to produce
paper. Recently, hemp fibers
have also been applied for
lightweight construction in
the automotive industry and
for insulating materials.
5 Hemp oil is a valuable
vegetable oil. It is obtained
from the hemp seeds, which
are first peeled by machine
and then “cold”, pressed, i.e.
at 40–60 °C. The oil content
of the seeds is up to 35%;
the press cake contains a lot
of protein and serves as feed
for animals or as a tonic for
athletes. Hemp oil contains
up to 80% polyunsaturated
fatty acids, especially linoleic
and linolenic acid, and is
therefore a valuable food oil:
The nutty taste is favoured
for the preparation of
salads, dressings and sauces.
Nowadays, hemp seeds are
also used in mueslis and
chocolates.
5 The essential hemp oil must
not be mixed up with the
hemp oil just described.
The essential hemp oil
is obtained by steam
distillation of the leaves
and flowers of the hemp
plant; the main production
takes place in Canada. It
contains numerous monoand sesquiterpenes such as
myrcene, pinene, limonene
and farnesene. We will learn
more about this group of
compounds in 7 Chap. 12.
The essential hemp oil is
used, e.g. for the production
of cough sweets as well as
massage or skin oils.
5 Most readers will have
remembered a fourth
possible use of the hemp
plant at the latest in its Latin
name - cannabis sativa - ,
its use as a medicine and
drug. The crushed blossom
bunches and the small
leaves of the hemp plant are
called “marijuana” or “grass”;
the resin extracted from
them is also called “hash”.
The pharmacological,
intoxicating effect
of cannabis is due to
ingredients known as
cannabinoids, most notably
(−)-Δ 9 -trans-tetrahydrocannabinol (THC), whose
structural formula is shown
in . Fig. 7.4.
Worldwide, there were an
estimated 180 million users of
cannabis as an illicit drug in 2017.
The main export countries for the
European cannabis market are
North Africa, especially Morocco,
Southwest Asia, especially
Afghanistan, as well as Albania,
Lebanon and South Africa.
In 1961, the cultivation
of cannabis was banned
worldwide by a United Nations
convention. In the meantime,
the regulations in the individual
countries have relaxed
considerably: In Canada and
Uruguay, for example, the sale
and consumption of cannabis
has been legalized. In many
countries - including Germany -
the use of cannabis for medical
purposes was permitted. In
Europe, the cultivation of
industrial hemp has increased
significantly in recent years,
from 8000 ha in 2011 to about
47,000 ha in 2017. Will hemp
become a billion dollar business
worldwide?
Chapter 7 · From Wood to Pulp - Cellulose
7
BOX: Hemp - A Plant with Many Faces
Hemp (Cannabis sativa) is one
of the oldest crops on earth:
Archeologists found fibers of
wild hemp in a cave which are
already about 30,000 years old.
The first systematic cultivation
of hemp probably took place
6000 years ago in China. Hemp
has been known in Europe since
ancient times and has been
cultivated and intensively used
as an important renewable
raw material in many regions.
Advantageously, hemp can be
cultivated without difficulty since
it is resistant to pests (. Fig. 7.3).
The different parts of the
hemp plant can be used very
differently:
5 The fibers of the hemp
stalks are an important raw
material for resistant textiles
as well as for ship ropes
and rigging. As already
practiced by the Chinese
in ancient times, hemp can
also be used to produce
paper. Recently, hemp fibers
have also been applied for
lightweight construction in
the automotive industry and
for insulating materials.
5 Hemp oil is a valuable
vegetable oil. It is obtained
from the hemp seeds, which
are first peeled by machine
and then “cold”, pressed, i.e.
at 40–60 °C. The oil content
of the seeds is up to 35%;
the press cake contains a lot
of protein and serves as feed
for animals or as a tonic for
athletes. Hemp oil contains
up to 80% polyunsaturated
fatty acids, especially linoleic
and linolenic acid, and is
therefore a valuable food oil:
The nutty taste is favoured
for the preparation of
salads, dressings and sauces.
Nowadays, hemp seeds are
also used in mueslis and
chocolates.
5 The essential hemp oil must
not be mixed up with the
hemp oil just described.
The essential hemp oil
is obtained by steam
distillation of the leaves
and flowers of the hemp
plant; the main production
takes place in Canada. It
contains numerous monoand sesquiterpenes such as
myrcene, pinene, limonene
and farnesene. We will learn
more about this group of
compounds in 7 Chap. 12.
The essential hemp oil is
used, e.g. for the production
of cough sweets as well as
massage or skin oils.
5 Most readers will have
remembered a fourth
possible use of the hemp
plant at the latest in its Latin
name - cannabis sativa - ,
its use as a medicine and
drug. The crushed blossom
bunches and the small
leaves of the hemp plant are
called “marijuana” or “grass”;
the resin extracted from
them is also called “hash”.
The pharmacological,
intoxicating effect
of cannabis is due to
ingredients known as
cannabinoids, most notably
(−)-Δ 9 -trans-tetrahydrocannabinol (THC), whose
structural formula is shown
in . Fig. 7.4.
Worldwide, there were an
estimated 180 million users of
cannabis as an illicit drug in 2017.
The main export countries for the
European cannabis market are
North Africa, especially Morocco,
Southwest Asia, especially
Afghanistan, as well as Albania,
Lebanon and South Africa.
In 1961, the cultivation
of cannabis was banned
worldwide by a United Nations
convention. In the meantime,
the regulations in the individual
countries have relaxed
considerably: In Canada and
Uruguay, for example, the sale
and consumption of cannabis
has been legalized. In many
countries - including Germany -
the use of cannabis for medical
purposes was permitted. In
Europe, the cultivation of
industrial hemp has increased
significantly in recent years,
from 8000 ha in 2011 to about
47,000 ha in 2017. Will hemp
become a billion dollar business
worldwide?